Six-year-old Maya Turner was all smiles as she showed the royal the handwritten letter she wrote thanking the prince for giving his mother, RAF Sgt. Michelle Turner, the opportunity to participate in the Games.

Michelle, 38, has a heart condition and was selected for the swimming and rowing teams.

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The letter read, “I was very proud of mummy and every other brave boy and girl. Thank you Help for Heroes and Prince Harry for helping my mummy and her friends.”

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At the launch ceremony at the Tower of London, Harry, a former Army officer, gave a powerful speech, telling the competitors: “It’s not about medals, it’s about taking part. Every single one of you are ambassadors for the Invictus Games.

“When you cross the finish line regardless of where you position is, I know exactly what all you guys are going to do, you’ll turn around and you’ll congratulate every single person who comes over that line regardless of what strip they’re wearing.”

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The Invictus Games is an international Paralympic-style multi-sport event created by Prince Harry in 2014 “to demonstrate the power of sports to inspire recovery, support rehabilitation and to demonstrate life beyond disability.”

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Chatting to the U.K.’s 90-strong team of wounded, injured and sick service personnel, both serving and veterans, the prince said: “It’s going to be good. Whether you get a medal or not you are going to have an amazing experience. Suck up all the experiences.

“For your family, your loved one, your friends, everything has changed too. Their aspirations may have been changed as much as yours. They will have made sacrifices too. This is a chance to thank them too. Thank them for the sacrifices they have also made.

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“No matter how you are going to do I promise you that you will feel a million dollars. Whether you cross the finishing line first or last will make no difference to me or to anyone.

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“This is a real opportunity for you guys to be congratulated and recognized for the amazing things you have done and the amazing things you are doing and will go on to do.”

The U.K. is one of 17 nations that will be taking part in the third Invictus Games from Sept. 23-30 in Toronto.